docs: def rotvec(v1, angle, iaxis):
      """
      Transform a vector to a new coordinate system rotated by angle
      radians about axis iaxis.  This transformation rotates v1 by
      angle radians about the specified axis.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/rotvec_c.html
  
      :param v1: Vector whose coordinate system is to be rotated.
      :type v1: 3-Element Array of floats
      :param angle: Angle of rotation (radians).
      :type angle: float
      :param iaxis: Axis of rotation X=1, Y=2, Z=3.
      :type iaxis: int
      :return: the vector expressed in the new coordinate system.
      :rtype: 3-Element Array of floats
      """
      v1 = stypes.toDoubleVector(v1)
      angle = ctypes.c_double(angle)
      iaxis = ctypes.c_int(iaxis)
      vout = stypes.emptyDoubleVector(3)
      libspice.rotvec_c(v1, angle, iaxis, vout)
      return stypes.cVectorToPython(vout)